tests/unit/test-fdmon-epoll.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * fdmon-epoll tests
   4  *
   5  * Copyright (c) 2020 Red Hat, Inc.
   6  */
   7
   8 #include "qemu/osdep.h"
   9 #include "block/aio.h"
  10 #include "qapi/error.h"
  11 #include "qemu/main-loop.h"
  12
  13 static AioContext *ctx;
  14
  15 static void dummy_fd_handler(EventNotifier *notifier)
  16 {
  17     event_notifier_test_and_clear(notifier);
  18 }
  19
  20 static void add_event_notifiers(EventNotifier *notifiers, size_t n)
  21 {
  22     for (size_t i = 0; i < n; i++) {
  23         event_notifier_init(&notifiers[i], false);
  24         aio_set_event_notifier(ctx, &notifiers[i], false,
  25                                dummy_fd_handler, NULL);
  26     }
  27 }
  28
  29 static void remove_event_notifiers(EventNotifier *notifiers, size_t n)
  30 {
  31     for (size_t i = 0; i < n; i++) {
  32         aio_set_event_notifier(ctx, &notifiers[i], false, NULL, NULL);
  33         event_notifier_cleanup(&notifiers[i]);
  34     }
  35 }
  36
  37 /* Check that fd handlers work when external clients are disabled */
  38 static void test_external_disabled(void)
  39 {
  40     EventNotifier notifiers[100];
  41
  42     /* fdmon-epoll is only enabled when many fd handlers are registered */
  43     add_event_notifiers(notifiers, G_N_ELEMENTS(notifiers));
  44
  45     event_notifier_set(&notifiers[0]);
  46     assert(aio_poll(ctx, true));
  47
  48     aio_disable_external(ctx);
  49     event_notifier_set(&notifiers[0]);
  50     assert(aio_poll(ctx, true));
  51     aio_enable_external(ctx);
  52
  53     remove_event_notifiers(notifiers, G_N_ELEMENTS(notifiers));
  54 }
  55
  56 int main(int argc, char **argv)
  57 {
  58     /*
  59      * This code relies on the fact that fdmon-io_uring disables itself when
  60      * the glib main loop is in use. The main loop uses fdmon-poll and upgrades
  61      * to fdmon-epoll when the number of fds exceeds a threshold.
  62      */
  63     qemu_init_main_loop(&error_fatal);
  64     ctx = qemu_get_aio_context();
  65
  66     while (g_main_context_iteration(NULL, false)) {
  67         /* Do nothing */
  68     }
  69
  70     g_test_init(&argc, &argv, NULL);
  71     g_test_add_func("/fdmon-epoll/external-disabled", test_external_disabled);
  72     return g_test_run();
  73 }